xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/config/i386/driver-i386.c (revision 63aea4bd5b445e491ff0389fe27ec78b3099dba3)
1 /* Subroutines for the gcc driver.
2    Copyright (C) 2006-2013 Free Software Foundation, Inc.
3 
4 This file is part of GCC.
5 
6 GCC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
9 any later version.
10 
11 GCC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 GNU General Public License for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3.  If not see
18 <http://www.gnu.org/licenses/>.  */
19 
20 #include "config.h"
21 #include "system.h"
22 #include "coretypes.h"
23 #include "tm.h"
24 
25 const char *host_detect_local_cpu (int argc, const char **argv);
26 
27 #ifdef __GNUC__
28 #include "cpuid.h"
29 
30 struct cache_desc
31 {
32   unsigned sizekb;
33   unsigned assoc;
34   unsigned line;
35 };
36 
37 /* Returns command line parameters that describe size and
38    cache line size of the processor caches.  */
39 
40 static char *
41 describe_cache (struct cache_desc level1, struct cache_desc level2)
42 {
43   char size[100], line[100], size2[100];
44 
45   /* At the moment, gcc does not use the information
46      about the associativity of the cache.  */
47 
48   snprintf (size, sizeof (size),
49 	    "--param l1-cache-size=%u ", level1.sizekb);
50   snprintf (line, sizeof (line),
51 	    "--param l1-cache-line-size=%u ", level1.line);
52 
53   snprintf (size2, sizeof (size2),
54 	    "--param l2-cache-size=%u ", level2.sizekb);
55 
56   return concat (size, line, size2, NULL);
57 }
58 
59 /* Detect L2 cache parameters using CPUID extended function 0x80000006.  */
60 
61 static void
62 detect_l2_cache (struct cache_desc *level2)
63 {
64   unsigned eax, ebx, ecx, edx;
65   unsigned assoc;
66 
67   __cpuid (0x80000006, eax, ebx, ecx, edx);
68 
69   level2->sizekb = (ecx >> 16) & 0xffff;
70   level2->line = ecx & 0xff;
71 
72   assoc = (ecx >> 12) & 0xf;
73   if (assoc == 6)
74     assoc = 8;
75   else if (assoc == 8)
76     assoc = 16;
77   else if (assoc >= 0xa && assoc <= 0xc)
78     assoc = 32 + (assoc - 0xa) * 16;
79   else if (assoc >= 0xd && assoc <= 0xe)
80     assoc = 96 + (assoc - 0xd) * 32;
81 
82   level2->assoc = assoc;
83 }
84 
85 /* Returns the description of caches for an AMD processor.  */
86 
87 static const char *
88 detect_caches_amd (unsigned max_ext_level)
89 {
90   unsigned eax, ebx, ecx, edx;
91 
92   struct cache_desc level1, level2 = {0, 0, 0};
93 
94   if (max_ext_level < 0x80000005)
95     return "";
96 
97   __cpuid (0x80000005, eax, ebx, ecx, edx);
98 
99   level1.sizekb = (ecx >> 24) & 0xff;
100   level1.assoc = (ecx >> 16) & 0xff;
101   level1.line = ecx & 0xff;
102 
103   if (max_ext_level >= 0x80000006)
104     detect_l2_cache (&level2);
105 
106   return describe_cache (level1, level2);
107 }
108 
109 /* Decodes the size, the associativity and the cache line size of
110    L1/L2 caches of an Intel processor.  Values are based on
111    "Intel Processor Identification and the CPUID Instruction"
112    [Application Note 485], revision -032, December 2007.  */
113 
114 static void
115 decode_caches_intel (unsigned reg, bool xeon_mp,
116 		     struct cache_desc *level1, struct cache_desc *level2)
117 {
118   int i;
119 
120   for (i = 24; i >= 0; i -= 8)
121     switch ((reg >> i) & 0xff)
122       {
123       case 0x0a:
124 	level1->sizekb = 8; level1->assoc = 2; level1->line = 32;
125 	break;
126       case 0x0c:
127 	level1->sizekb = 16; level1->assoc = 4; level1->line = 32;
128 	break;
129       case 0x0d:
130 	level1->sizekb = 16; level1->assoc = 4; level1->line = 64;
131 	break;
132       case 0x0e:
133 	level1->sizekb = 24; level1->assoc = 6; level1->line = 64;
134 	break;
135       case 0x21:
136 	level2->sizekb = 256; level2->assoc = 8; level2->line = 64;
137 	break;
138       case 0x24:
139 	level2->sizekb = 1024; level2->assoc = 16; level2->line = 64;
140 	break;
141       case 0x2c:
142 	level1->sizekb = 32; level1->assoc = 8; level1->line = 64;
143 	break;
144       case 0x39:
145 	level2->sizekb = 128; level2->assoc = 4; level2->line = 64;
146 	break;
147       case 0x3a:
148 	level2->sizekb = 192; level2->assoc = 6; level2->line = 64;
149 	break;
150       case 0x3b:
151 	level2->sizekb = 128; level2->assoc = 2; level2->line = 64;
152 	break;
153       case 0x3c:
154 	level2->sizekb = 256; level2->assoc = 4; level2->line = 64;
155 	break;
156       case 0x3d:
157 	level2->sizekb = 384; level2->assoc = 6; level2->line = 64;
158 	break;
159       case 0x3e:
160 	level2->sizekb = 512; level2->assoc = 4; level2->line = 64;
161 	break;
162       case 0x41:
163 	level2->sizekb = 128; level2->assoc = 4; level2->line = 32;
164 	break;
165       case 0x42:
166 	level2->sizekb = 256; level2->assoc = 4; level2->line = 32;
167 	break;
168       case 0x43:
169 	level2->sizekb = 512; level2->assoc = 4; level2->line = 32;
170 	break;
171       case 0x44:
172 	level2->sizekb = 1024; level2->assoc = 4; level2->line = 32;
173 	break;
174       case 0x45:
175 	level2->sizekb = 2048; level2->assoc = 4; level2->line = 32;
176 	break;
177       case 0x48:
178 	level2->sizekb = 3072; level2->assoc = 12; level2->line = 64;
179 	break;
180       case 0x49:
181 	if (xeon_mp)
182 	  break;
183 	level2->sizekb = 4096; level2->assoc = 16; level2->line = 64;
184 	break;
185       case 0x4e:
186 	level2->sizekb = 6144; level2->assoc = 24; level2->line = 64;
187 	break;
188       case 0x60:
189 	level1->sizekb = 16; level1->assoc = 8; level1->line = 64;
190 	break;
191       case 0x66:
192 	level1->sizekb = 8; level1->assoc = 4; level1->line = 64;
193 	break;
194       case 0x67:
195 	level1->sizekb = 16; level1->assoc = 4; level1->line = 64;
196 	break;
197       case 0x68:
198 	level1->sizekb = 32; level1->assoc = 4; level1->line = 64;
199 	break;
200       case 0x78:
201 	level2->sizekb = 1024; level2->assoc = 4; level2->line = 64;
202 	break;
203       case 0x79:
204 	level2->sizekb = 128; level2->assoc = 8; level2->line = 64;
205 	break;
206       case 0x7a:
207 	level2->sizekb = 256; level2->assoc = 8; level2->line = 64;
208 	break;
209       case 0x7b:
210 	level2->sizekb = 512; level2->assoc = 8; level2->line = 64;
211 	break;
212       case 0x7c:
213 	level2->sizekb = 1024; level2->assoc = 8; level2->line = 64;
214 	break;
215       case 0x7d:
216 	level2->sizekb = 2048; level2->assoc = 8; level2->line = 64;
217 	break;
218       case 0x7f:
219 	level2->sizekb = 512; level2->assoc = 2; level2->line = 64;
220 	break;
221       case 0x80:
222 	level2->sizekb = 512; level2->assoc = 8; level2->line = 64;
223 	break;
224       case 0x82:
225 	level2->sizekb = 256; level2->assoc = 8; level2->line = 32;
226 	break;
227       case 0x83:
228 	level2->sizekb = 512; level2->assoc = 8; level2->line = 32;
229 	break;
230       case 0x84:
231 	level2->sizekb = 1024; level2->assoc = 8; level2->line = 32;
232 	break;
233       case 0x85:
234 	level2->sizekb = 2048; level2->assoc = 8; level2->line = 32;
235 	break;
236       case 0x86:
237 	level2->sizekb = 512; level2->assoc = 4; level2->line = 64;
238 	break;
239       case 0x87:
240 	level2->sizekb = 1024; level2->assoc = 8; level2->line = 64;
241 
242       default:
243 	break;
244       }
245 }
246 
247 /* Detect cache parameters using CPUID function 2.  */
248 
249 static void
250 detect_caches_cpuid2 (bool xeon_mp,
251 		      struct cache_desc *level1, struct cache_desc *level2)
252 {
253   unsigned regs[4];
254   int nreps, i;
255 
256   __cpuid (2, regs[0], regs[1], regs[2], regs[3]);
257 
258   nreps = regs[0] & 0x0f;
259   regs[0] &= ~0x0f;
260 
261   while (--nreps >= 0)
262     {
263       for (i = 0; i < 4; i++)
264 	if (regs[i] && !((regs[i] >> 31) & 1))
265 	  decode_caches_intel (regs[i], xeon_mp, level1, level2);
266 
267       if (nreps)
268 	__cpuid (2, regs[0], regs[1], regs[2], regs[3]);
269     }
270 }
271 
272 /* Detect cache parameters using CPUID function 4. This
273    method doesn't require hardcoded tables.  */
274 
275 enum cache_type
276 {
277   CACHE_END = 0,
278   CACHE_DATA = 1,
279   CACHE_INST = 2,
280   CACHE_UNIFIED = 3
281 };
282 
283 static void
284 detect_caches_cpuid4 (struct cache_desc *level1, struct cache_desc *level2,
285 		      struct cache_desc *level3)
286 {
287   struct cache_desc *cache;
288 
289   unsigned eax, ebx, ecx, edx;
290   int count;
291 
292   for (count = 0;; count++)
293     {
294       __cpuid_count(4, count, eax, ebx, ecx, edx);
295       switch (eax & 0x1f)
296 	{
297 	case CACHE_END:
298 	  return;
299 	case CACHE_DATA:
300 	case CACHE_UNIFIED:
301 	  {
302 	    switch ((eax >> 5) & 0x07)
303 	      {
304 	      case 1:
305 		cache = level1;
306 		break;
307 	      case 2:
308 		cache = level2;
309 		break;
310 	      case 3:
311 		cache = level3;
312 		break;
313 	      default:
314 		cache = NULL;
315 	      }
316 
317 	    if (cache)
318 	      {
319 		unsigned sets = ecx + 1;
320 		unsigned part = ((ebx >> 12) & 0x03ff) + 1;
321 
322 		cache->assoc = ((ebx >> 22) & 0x03ff) + 1;
323 		cache->line = (ebx & 0x0fff) + 1;
324 
325 		cache->sizekb = (cache->assoc * part
326 				 * cache->line * sets) / 1024;
327 	      }
328 	  }
329 	default:
330 	  break;
331 	}
332     }
333 }
334 
335 /* Returns the description of caches for an Intel processor.  */
336 
337 static const char *
338 detect_caches_intel (bool xeon_mp, unsigned max_level,
339 		     unsigned max_ext_level, unsigned *l2sizekb)
340 {
341   struct cache_desc level1 = {0, 0, 0}, level2 = {0, 0, 0}, level3 = {0, 0, 0};
342 
343   if (max_level >= 4)
344     detect_caches_cpuid4 (&level1, &level2, &level3);
345   else if (max_level >= 2)
346     detect_caches_cpuid2 (xeon_mp, &level1, &level2);
347   else
348     return "";
349 
350   if (level1.sizekb == 0)
351     return "";
352 
353   /* Let the L3 replace the L2. This assumes inclusive caches
354      and single threaded program for now. */
355   if (level3.sizekb)
356     level2 = level3;
357 
358   /* Intel CPUs are equipped with AMD style L2 cache info.  Try this
359      method if other methods fail to provide L2 cache parameters.  */
360   if (level2.sizekb == 0 && max_ext_level >= 0x80000006)
361     detect_l2_cache (&level2);
362 
363   *l2sizekb = level2.sizekb;
364 
365   return describe_cache (level1, level2);
366 }
367 
368 /* This will be called by the spec parser in gcc.c when it sees
369    a %:local_cpu_detect(args) construct.  Currently it will be called
370    with either "arch" or "tune" as argument depending on if -march=native
371    or -mtune=native is to be substituted.
372 
373    It returns a string containing new command line parameters to be
374    put at the place of the above two options, depending on what CPU
375    this is executed.  E.g. "-march=k8" on an AMD64 machine
376    for -march=native.
377 
378    ARGC and ARGV are set depending on the actual arguments given
379    in the spec.  */
380 
381 const char *host_detect_local_cpu (int argc, const char **argv)
382 {
383   enum processor_type processor = PROCESSOR_I386;
384   const char *cpu = "i386";
385 
386   const char *cache = "";
387   const char *options = "";
388 
389   unsigned int eax, ebx, ecx, edx;
390 
391   unsigned int max_level, ext_level;
392 
393   unsigned int vendor;
394   unsigned int model, family;
395 
396   unsigned int has_sse3, has_ssse3, has_cmpxchg16b;
397   unsigned int has_cmpxchg8b, has_cmov, has_mmx, has_sse, has_sse2;
398 
399   /* Extended features */
400   unsigned int has_lahf_lm = 0, has_sse4a = 0;
401   unsigned int has_longmode = 0, has_3dnowp = 0, has_3dnow = 0;
402   unsigned int has_movbe = 0, has_sse4_1 = 0, has_sse4_2 = 0;
403   unsigned int has_popcnt = 0, has_aes = 0, has_avx = 0, has_avx2 = 0;
404   unsigned int has_pclmul = 0, has_abm = 0, has_lwp = 0;
405   unsigned int has_fma = 0, has_fma4 = 0, has_xop = 0;
406   unsigned int has_bmi = 0, has_bmi2 = 0, has_tbm = 0, has_lzcnt = 0;
407   unsigned int has_hle = 0, has_rtm = 0;
408   unsigned int has_rdrnd = 0, has_f16c = 0, has_fsgsbase = 0;
409   unsigned int has_rdseed = 0, has_prfchw = 0, has_adx = 0;
410   unsigned int has_osxsave = 0, has_fxsr = 0, has_xsave = 0, has_xsaveopt = 0;
411 
412   bool arch;
413 
414   unsigned int l2sizekb = 0;
415 
416   if (argc < 1)
417     return NULL;
418 
419   arch = !strcmp (argv[0], "arch");
420 
421   if (!arch && strcmp (argv[0], "tune"))
422     return NULL;
423 
424   max_level = __get_cpuid_max (0, &vendor);
425   if (max_level < 1)
426     goto done;
427 
428   __cpuid (1, eax, ebx, ecx, edx);
429 
430   model = (eax >> 4) & 0x0f;
431   family = (eax >> 8) & 0x0f;
432   if (vendor == signature_INTEL_ebx)
433     {
434       unsigned int extended_model, extended_family;
435 
436       extended_model = (eax >> 12) & 0xf0;
437       extended_family = (eax >> 20) & 0xff;
438       if (family == 0x0f)
439 	{
440 	  family += extended_family;
441 	  model += extended_model;
442 	}
443       else if (family == 0x06)
444 	model += extended_model;
445     }
446 
447   has_sse3 = ecx & bit_SSE3;
448   has_ssse3 = ecx & bit_SSSE3;
449   has_sse4_1 = ecx & bit_SSE4_1;
450   has_sse4_2 = ecx & bit_SSE4_2;
451   has_avx = ecx & bit_AVX;
452   has_osxsave = ecx & bit_OSXSAVE;
453   has_cmpxchg16b = ecx & bit_CMPXCHG16B;
454   has_movbe = ecx & bit_MOVBE;
455   has_popcnt = ecx & bit_POPCNT;
456   has_aes = ecx & bit_AES;
457   has_pclmul = ecx & bit_PCLMUL;
458   has_fma = ecx & bit_FMA;
459   has_f16c = ecx & bit_F16C;
460   has_rdrnd = ecx & bit_RDRND;
461   has_xsave = ecx & bit_XSAVE;
462 
463   has_cmpxchg8b = edx & bit_CMPXCHG8B;
464   has_cmov = edx & bit_CMOV;
465   has_mmx = edx & bit_MMX;
466   has_fxsr = edx & bit_FXSAVE;
467   has_sse = edx & bit_SSE;
468   has_sse2 = edx & bit_SSE2;
469 
470   if (max_level >= 7)
471     {
472       __cpuid_count (7, 0, eax, ebx, ecx, edx);
473 
474       has_bmi = ebx & bit_BMI;
475       has_hle = ebx & bit_HLE;
476       has_rtm = ebx & bit_RTM;
477       has_avx2 = ebx & bit_AVX2;
478       has_bmi2 = ebx & bit_BMI2;
479       has_fsgsbase = ebx & bit_FSGSBASE;
480       has_rdseed = ebx & bit_RDSEED;
481       has_adx = ebx & bit_ADX;
482     }
483 
484   if (max_level >= 13)
485     {
486       __cpuid_count (13, 1, eax, ebx, ecx, edx);
487 
488       has_xsaveopt = eax & bit_XSAVEOPT;
489     }
490 
491   /* Check cpuid level of extended features.  */
492   __cpuid (0x80000000, ext_level, ebx, ecx, edx);
493 
494   if (ext_level > 0x80000000)
495     {
496       __cpuid (0x80000001, eax, ebx, ecx, edx);
497 
498       has_lahf_lm = ecx & bit_LAHF_LM;
499       has_sse4a = ecx & bit_SSE4a;
500       has_abm = ecx & bit_ABM;
501       has_lwp = ecx & bit_LWP;
502       has_fma4 = ecx & bit_FMA4;
503       has_xop = ecx & bit_XOP;
504       has_tbm = ecx & bit_TBM;
505       has_lzcnt = ecx & bit_LZCNT;
506       has_prfchw = ecx & bit_PRFCHW;
507 
508       has_longmode = edx & bit_LM;
509       has_3dnowp = edx & bit_3DNOWP;
510       has_3dnow = edx & bit_3DNOW;
511     }
512 
513   /* Get XCR_XFEATURE_ENABLED_MASK register with xgetbv.  */
514 #define XCR_XFEATURE_ENABLED_MASK	0x0
515 #define XSTATE_FP			0x1
516 #define XSTATE_SSE			0x2
517 #define XSTATE_YMM			0x4
518   if (has_osxsave)
519     asm (".byte 0x0f; .byte 0x01; .byte 0xd0"
520 	 : "=a" (eax), "=d" (edx)
521 	 : "c" (XCR_XFEATURE_ENABLED_MASK));
522 
523   /* Check if SSE and YMM states are supported.  */
524   if (!has_osxsave
525       || (eax & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM))
526     {
527       has_avx = 0;
528       has_avx2 = 0;
529       has_fma = 0;
530       has_fma4 = 0;
531       has_f16c = 0;
532       has_xop = 0;
533       has_xsave = 0;
534       has_xsaveopt = 0;
535     }
536 
537   if (!arch)
538     {
539       if (vendor == signature_AMD_ebx
540 	  || vendor == signature_CENTAUR_ebx
541 	  || vendor == signature_CYRIX_ebx
542 	  || vendor == signature_NSC_ebx)
543 	cache = detect_caches_amd (ext_level);
544       else if (vendor == signature_INTEL_ebx)
545 	{
546 	  bool xeon_mp = (family == 15 && model == 6);
547 	  cache = detect_caches_intel (xeon_mp, max_level,
548 				       ext_level, &l2sizekb);
549 	}
550     }
551 
552   if (vendor == signature_AMD_ebx)
553     {
554       unsigned int name;
555 
556       /* Detect geode processor by its processor signature.  */
557       if (ext_level > 0x80000001)
558 	__cpuid (0x80000002, name, ebx, ecx, edx);
559       else
560 	name = 0;
561 
562       if (name == signature_NSC_ebx)
563 	processor = PROCESSOR_GEODE;
564       else if (has_movbe)
565 	processor = PROCESSOR_BTVER2;
566       else if (has_xsaveopt)
567         processor = PROCESSOR_BDVER3;
568       else if (has_bmi)
569         processor = PROCESSOR_BDVER2;
570       else if (has_xop)
571 	processor = PROCESSOR_BDVER1;
572       else if (has_sse4a && has_ssse3)
573         processor = PROCESSOR_BTVER1;
574       else if (has_sse4a)
575 	processor = PROCESSOR_AMDFAM10;
576       else if (has_sse2 || has_longmode)
577 	processor = PROCESSOR_K8;
578       else if (has_3dnowp && family == 6)
579 	processor = PROCESSOR_ATHLON;
580       else if (has_mmx)
581 	processor = PROCESSOR_K6;
582       else
583 	processor = PROCESSOR_PENTIUM;
584     }
585   else if (vendor == signature_CENTAUR_ebx)
586     {
587       if (arch)
588 	{
589 	  switch (family)
590 	    {
591 	    case 6:
592 	      if (model > 9)
593 		/* Use the default detection procedure.  */
594 		processor = PROCESSOR_GENERIC32;
595 	      else if (model == 9)
596 		cpu = "c3-2";
597 	      else if (model >= 6)
598 		cpu = "c3";
599 	      else
600 		processor = PROCESSOR_GENERIC32;
601 	      break;
602 	    case 5:
603 	      if (has_3dnow)
604 		cpu = "winchip2";
605 	      else if (has_mmx)
606 		cpu = "winchip2-c6";
607 	      else
608 		processor = PROCESSOR_GENERIC32;
609 	      break;
610 	    default:
611 	      /* We have no idea.  */
612 	      processor = PROCESSOR_GENERIC32;
613 	    }
614 	}
615     }
616   else
617     {
618       switch (family)
619 	{
620 	case 4:
621 	  processor = PROCESSOR_I486;
622 	  break;
623 	case 5:
624 	  processor = PROCESSOR_PENTIUM;
625 	  break;
626 	case 6:
627 	  processor = PROCESSOR_PENTIUMPRO;
628 	  break;
629 	case 15:
630 	  processor = PROCESSOR_PENTIUM4;
631 	  break;
632 	default:
633 	  /* We have no idea.  */
634 	  processor = PROCESSOR_GENERIC32;
635 	}
636     }
637 
638   switch (processor)
639     {
640     case PROCESSOR_I386:
641       /* Default.  */
642       break;
643     case PROCESSOR_I486:
644       cpu = "i486";
645       break;
646     case PROCESSOR_PENTIUM:
647       if (arch && has_mmx)
648 	cpu = "pentium-mmx";
649       else
650 	cpu = "pentium";
651       break;
652     case PROCESSOR_PENTIUMPRO:
653       switch (model)
654 	{
655 	case 0x1c:
656 	case 0x26:
657 	  /* Atom.  */
658 	  cpu = "atom";
659 	  break;
660 	case 0x0f:
661 	  /* Merom.  */
662 	case 0x17:
663 	case 0x1d:
664 	  /* Penryn.  */
665 	  cpu = "core2";
666 	  break;
667 	case 0x1a:
668 	case 0x1e:
669 	case 0x1f:
670 	case 0x2e:
671 	  /* Nehalem.  */
672 	case 0x25:
673 	case 0x2c:
674 	case 0x2f:
675 	  /* Westmere.  */
676 	  cpu = "corei7";
677 	  break;
678 	case 0x2a:
679 	case 0x2d:
680 	  /* Sandy Bridge.  */
681 	  cpu = "corei7-avx";
682 	  break;
683 	case 0x3a:
684 	case 0x3e:
685 	  /* Ivy Bridge.  */
686 	  cpu = "core-avx-i";
687 	  break;
688 	case 0x3c:
689 	case 0x45:
690 	case 0x46:
691 	  /* Haswell.  */
692 	  cpu = "core-avx2";
693 	  break;
694 	default:
695 	  if (arch)
696 	    {
697 	      /* This is unknown family 0x6 CPU.  */
698 	      if (has_avx2)
699 		/* Assume Haswell.  */
700 		cpu = "core-avx2";
701 	      else if (has_avx)
702 		/* Assume Sandy Bridge.  */
703 		cpu = "corei7-avx";
704 	      else if (has_sse4_2)
705 		/* Assume Core i7.  */
706 		cpu = "corei7";
707 	      else if (has_ssse3)
708 		{
709 		  if (has_movbe)
710 		    /* Assume Atom.  */
711 		    cpu = "atom";
712 		  else
713 		    /* Assume Core 2.  */
714 		    cpu = "core2";
715 		}
716 	      else if (has_longmode)
717 		/* Perhaps some emulator?  Assume x86-64, otherwise gcc
718 		   -march=native would be unusable for 64-bit compilations,
719 		   as all the CPUs below are 32-bit only.  */
720 		cpu = "x86-64";
721 	      else if (has_sse3)
722 		/* It is Core Duo.  */
723 		cpu = "pentium-m";
724 	      else if (has_sse2)
725 		/* It is Pentium M.  */
726 		cpu = "pentium-m";
727 	      else if (has_sse)
728 		/* It is Pentium III.  */
729 		cpu = "pentium3";
730 	      else if (has_mmx)
731 		/* It is Pentium II.  */
732 		cpu = "pentium2";
733 	      else
734 		/* Default to Pentium Pro.  */
735 		cpu = "pentiumpro";
736 	    }
737 	  else
738 	    /* For -mtune, we default to -mtune=generic.  */
739 	    cpu = "generic";
740 	  break;
741 	}
742       break;
743     case PROCESSOR_PENTIUM4:
744       if (has_sse3)
745 	{
746 	  if (has_longmode)
747 	    cpu = "nocona";
748 	  else
749 	    cpu = "prescott";
750 	}
751       else
752 	cpu = "pentium4";
753       break;
754     case PROCESSOR_GEODE:
755       cpu = "geode";
756       break;
757     case PROCESSOR_K6:
758       if (arch && has_3dnow)
759 	cpu = "k6-3";
760       else
761 	cpu = "k6";
762       break;
763     case PROCESSOR_ATHLON:
764       if (arch && has_sse)
765 	cpu = "athlon-4";
766       else
767 	cpu = "athlon";
768       break;
769     case PROCESSOR_K8:
770       if (arch && has_sse3)
771 	cpu = "k8-sse3";
772       else
773 	cpu = "k8";
774       break;
775     case PROCESSOR_AMDFAM10:
776       cpu = "amdfam10";
777       break;
778     case PROCESSOR_BDVER1:
779       cpu = "bdver1";
780       break;
781     case PROCESSOR_BDVER2:
782       cpu = "bdver2";
783       break;
784     case PROCESSOR_BDVER3:
785       cpu = "bdver3";
786       break;
787     case PROCESSOR_BTVER1:
788       cpu = "btver1";
789       break;
790     case PROCESSOR_BTVER2:
791       cpu = "btver2";
792       break;
793 
794     default:
795       /* Use something reasonable.  */
796       if (arch)
797 	{
798 	  if (has_ssse3)
799 	    cpu = "core2";
800 	  else if (has_sse3)
801 	    {
802 	      if (has_longmode)
803 		cpu = "nocona";
804 	      else
805 		cpu = "prescott";
806 	    }
807 	  else if (has_sse2)
808 	    cpu = "pentium4";
809 	  else if (has_cmov)
810 	    cpu = "pentiumpro";
811 	  else if (has_mmx)
812 	    cpu = "pentium-mmx";
813 	  else if (has_cmpxchg8b)
814 	    cpu = "pentium";
815 	}
816       else
817 	cpu = "generic";
818     }
819 
820   if (arch)
821     {
822       const char *cx16 = has_cmpxchg16b ? " -mcx16" : " -mno-cx16";
823       const char *sahf = has_lahf_lm ? " -msahf" : " -mno-sahf";
824       const char *movbe = has_movbe ? " -mmovbe" : " -mno-movbe";
825       const char *ase = has_aes ? " -maes" : " -mno-aes";
826       const char *pclmul = has_pclmul ? " -mpclmul" : " -mno-pclmul";
827       const char *popcnt = has_popcnt ? " -mpopcnt" : " -mno-popcnt";
828       const char *abm = has_abm ? " -mabm" : " -mno-abm";
829       const char *lwp = has_lwp ? " -mlwp" : " -mno-lwp";
830       const char *fma = has_fma ? " -mfma" : " -mno-fma";
831       const char *fma4 = has_fma4 ? " -mfma4" : " -mno-fma4";
832       const char *xop = has_xop ? " -mxop" : " -mno-xop";
833       const char *bmi = has_bmi ? " -mbmi" : " -mno-bmi";
834       const char *bmi2 = has_bmi2 ? " -mbmi2" : " -mno-bmi2";
835       const char *tbm = has_tbm ? " -mtbm" : " -mno-tbm";
836       const char *avx = has_avx ? " -mavx" : " -mno-avx";
837       const char *avx2 = has_avx2 ? " -mavx2" : " -mno-avx2";
838       const char *sse4_2 = has_sse4_2 ? " -msse4.2" : " -mno-sse4.2";
839       const char *sse4_1 = has_sse4_1 ? " -msse4.1" : " -mno-sse4.1";
840       const char *lzcnt = has_lzcnt ? " -mlzcnt" : " -mno-lzcnt";
841       const char *hle = has_hle ? " -mhle" : " -mno-hle";
842       const char *rtm = has_rtm ? " -mrtm" : " -mno-rtm";
843       const char *rdrnd = has_rdrnd ? " -mrdrnd" : " -mno-rdrnd";
844       const char *f16c = has_f16c ? " -mf16c" : " -mno-f16c";
845       const char *fsgsbase = has_fsgsbase ? " -mfsgsbase" : " -mno-fsgsbase";
846       const char *rdseed = has_rdseed ? " -mrdseed" : " -mno-rdseed";
847       const char *prfchw = has_prfchw ? " -mprfchw" : " -mno-prfchw";
848       const char *adx = has_adx ? " -madx" : " -mno-adx";
849       const char *fxsr = has_fxsr ? " -mfxsr" : " -mno-fxsr";
850       const char *xsave = has_xsave ? " -mxsave" : " -mno-xsave";
851       const char *xsaveopt = has_xsaveopt ? " -mxsaveopt" : " -mno-xsaveopt";
852 
853       options = concat (options, cx16, sahf, movbe, ase, pclmul,
854 			popcnt, abm, lwp, fma, fma4, xop, bmi, bmi2,
855 			tbm, avx, avx2, sse4_2, sse4_1, lzcnt, rtm,
856 			hle, rdrnd, f16c, fsgsbase, rdseed, prfchw, adx,
857 			fxsr, xsave, xsaveopt, NULL);
858     }
859 
860 done:
861   return concat (cache, "-m", argv[0], "=", cpu, options, NULL);
862 }
863 #else
864 
865 /* If we aren't compiling with GCC then the driver will just ignore
866    -march and -mtune "native" target and will leave to the newly
867    built compiler to generate code for its default target.  */
868 
869 const char *host_detect_local_cpu (int argc ATTRIBUTE_UNUSED,
870 				   const char **argv ATTRIBUTE_UNUSED)
871 {
872   return NULL;
873 }
874 #endif /* __GNUC__ */
875